Line circuit with two-way transfer



June 26, 1962 c. E. L OMAX LINE CIRCUIT WITH Two-WAY TRANSFER 2 Sheets-Sheet 1 Filed Dec. 8, 1958 ATTY Filed Deo. 8, 1958 Jun 26, 1962 c. E. LoMAx 3,041,405

LINE CIRCUIT WITH Two-WAY TRANSFER 2 sheets-sheet 2 INVENTOR. CLARENCE E. LOMAX ATTY Unit

The present invention relates in general to telephone systems, `but more particularly to an arrangement for giving a telephone subscriber a special type of service referred to as transfer service. A service of this type is shown in Patent No. 2,095,712, issued to Edward S. Peterson on October `12, 1937, whereby a subscriber having this service is able to bring about a switching operation at the exchange, in effectk for any desired period,

which causes all calls intended for his telephone to be diverted to another telephone.

Doctors who do not have private secretaries and who cannot subscribe to public secretarial service are typical examples of telephone subscribers who need line transfer service. They have a telephone Iat their otce, a telephone at their residence, and the two telephones are on separate lines with two separate listed directory numbers. This arrangement is required so that both phones can be used simultaneously for either incoming or outgoing calls. In the above-mentioned Peterson patent, if the doctor leaves his cice to return to his residence, before leaving the ofce he operates a key to operate a transfer relay in the exchange to transfer all calls to his residence phone. Thus, only the residence telephone would ring on calls incoming to the ofce.

It is an object therefore of this invention to provide two telephone lines both of which have full automatic service and a timing means for timing a call to the rst line to cause the second line to be connected with it after a fixed period if the party on Vthe first line does not answer and if the second line is not busy.

It is another object of this invention to provide two telephone Ilines which both have full automatic service and a timer means for a call to the first line to start measuring time when it is called so as to later connect the second line with it, but including a means to Stop the timer if the second line becomes busy, and to again start the timer if the second line becomes free before the party on the iirst line answers.

lt is a further object of this invention to provide two lines which have full automatic service anda means for each line to connect the other line to it .after a xed 50 period if the call to it is not answered and if the other line is not busy.

It is a still further object of this invention to provide a residence line having two call directoryV numbers and two ringers at the same location, one ringer responding to calls from the first call number and the other to calls from the second call number, an office line having another call number, both lines having full automatic service, an understanding that the rst ringer on the rst line indicates that a certain person is wanted, and a means whereby the party on the first line can let the call go unanswered if the first ringer rings so that in due time the call will be transferred to the second line where it is known that the Wanted party is located.

Other objects and advantages will become apparent from a perusal of the following specification taken in combination with the accompanying drawings of which;

FIGS. l and 2, with FIG. 2 placed to the right, shows the apparatus involved and the manner in which it is installed in a typical telephone system.

Referring to the drawings, the reference letter A represents an automatic telephone station assumed to be at the office of a subscriber having the transfer service.

F'ice B is the residence telephone or any other telephone to which calls are to be transferred to or transferred from. The drawings, in greater detail, disclose a telephone line circuit common to Line l and Line 2, which are in turn individually connected to stations A and B respectively. The line circuit 100 comprises two sets of line, cut-off, and transfer control relays, with one set for each line, namely relays 110, 120, 125, and 134i" for Line 1, and relays 150, 160, 170, and y for Line 2. Also, a plurality of transfer relays Zltl, 220,' 230, 240, and 250 are common to both lines, as well as a timer 270'. The timer 270 comprises a motor magnet 260, which steps a plurality of cams C1-C4 one step for each `deenergization. A plurality of vertical lines Iassociated 'with the timer 27 designates six differentvstepped positions 1-6 of the cams, with each cam having a lug such as lug 294 on cam 1, engaging and disengaging a cam spring such as spring 284, only at certain stepped positions. The springs, in turn, control certain spring contacts.

The office station A has a ringer 7 connected to the negative side of the line to respond to a ringing frequency from a connector such as 5 with the otlice station A having a single directory call number on a terminal-per-station basis. The residence station B on the other hand has two fingers 8 and 9 with divided ringing and two directory call numbers for the one residence line. The connector bank terminals Y designating a call number for ringing over the negative side of the line to ring ringer 8, and a second set of bank terminals Z `designating a second call number for r'ingingover the positive side of the line to ring ringer 9. The two ringers at residence station B designate, one call number and Vone ringer 8 for doctors calls, and the other call number and ringer `9 is only for normal residence c-alls. In

' the detailed explanation to follow, if the doctors ringer S should ring and if it were known that the doctor was in his otlice, the call need not be answered, but a resident could wait for the timer 2701 to transfer the call to the oice station A. This would be advantageous to the patients in exchanges where metered service is used because the doctor, b-y paying for the transfer service, could save the patient the expense of a second call.

The timer 270, and more particularly the motor magnet 269, is pulsed one time `for each ringing period received over either one of the lines providing the other line is not busy, whereby, if after four ringing periods the called line. `does not answer, the call will be transferred to the other line and a ringer at both stations will ring simultaneously responsive to all ringing periods received thereafter. However, it should be pointed out that normal residential calls not -answered after four ringing periods would also transfer the call to fthe oce line, but since this ringing comes over the positive side of the line, the ringer at the office station B would not respond because it is connected to the negative side of the line. This last case is to prevent unnecessary disturbances of the doctor since he may be busy with patients, and since these calls were not intended for him anyway.

A plurality of meters are provided to meter calls for both Line 1 and Line 2. Only the leads extending to these meters are shown, and are for the following:

MTKl `for metering failures or delay in transferring to Line 1 MTR2 for metering failures or delay in transferring to Line 2 Y MTR3 for metering calls transferred to Line l.

MTR4 for metering calls transferred to Line `2` MTRS for totalizing incoming calls to Line 1 MTR6 for totalizing incoming calls to Line 2t By means of these meters the traffic load can bedetermined, such as a high reading of meter 1 and low reading of meter v3 indicates that many attempts to transfer to Line 1 are unsuccessful because Line 1 is busy too much of the time. lf, under these conditions, meter has a low reading, it indicates that outgoing calls from Line 1 are the cause of it being busy much of the time.

A more detailed explanation will now follow:

Assuming that the subscriber at the oice Station A Wishes to make an outgoing call, the removal of the handset closes a Vloop through the hook switch (not shown) to operate relay 129. The circuit extending from battery, winding of relay 120, contacts 1'11, negative conductor C12, through the callers loop, positive conductor C13, to ground at contacts 112. At contacts 121, relay 120 closes battery via'the winding of relay 110 to the control conductor C15 extending to the iinder 300. At contacts 122, ground is closed to mark Station A busy on the incoming connector bank via control conductor C14. Contacts 123 close an obvious circuit to relay 125. At contacts 124 ground is closed to the ST lead to start the line finder 39d to search for and find the marked line. Relay 125 operates, opens at-contacts 126 a prepared circuit to an incoming call totalizer meter. At contacts 127 relay 125 prepares a locking circuit for itself. When the calling line is found by the line finder, such as tinder 300, ground is closed over the iinder control lead C in a well-known manner to operate the cut-0E relay 110. Relay 110 in operating closes its X contacts first, closing at X contacts 115 -a holding circuit to relay 125, and at X contacts 114 closes a holding circuit for relay 110. Thereafter, contacts 111 and 112 open the circuit to relay 120, contacts 113 pre- `pares ground to the incoming call totalizer meter for Line 1. Contacts 116 opens ia prepared circuit to relay 180. Relay 120 restores, opening at contacts 121 the original operatingr circuit to relay 110'. However, as mentioned, relay 110 locked operated over its X contacts 114. Contacts 122 opens ground to control lead C14. However, at contacts 122 ground is replaced via control lead C15 from the nder. A selector switch (not shown) would be linked to the :Ender 300 and Would return dial tone in a wellknown manner, and the calling party at his oi'lice Station A would dial the desired directory number to extend the call in a Well-known manner over arswitch train.

Assuming that the same subscriber, When at his place of residence, Wishes to make 'a call from his residence Station B, the removal of the handset closes a loop through the hookswitch to operate relay 160. The circuit extending from battery, winding of relay 160, contacts 156, negative conductor C23, through lthe callers loop, positive conductor C24, contacts 155 to` ground. At contacts 161 relay 160 closes ground to the iinder start lead ST to start the linder inrsearch of the marked line, which is marked via battery through the winding of relay 150, contacts 162 being closed, and control conductor C26 to the nder bank. Contacts 163 closes ground to the incoming connector bank via conductor C25 to mark Station B busy to incoming calls. Contacts 165 close an obvious circuit to relay 1741. Relay 170 operates, closing contacts =171to prepare a holding circuit for itself. Contacts 173 opens a prepared circuit to the incoming totalizer meter for Line 2. When the marked line is found by the Vfinder such as finder 301, ground is returned over control conductor C26 to operate relay 150. Relay 150 upon operating, loperates its X contacts rst, closing at X contacts 152 'a locking circuit for itself, and at X contacts 153 closes a holding circuit to relay 170. Thereafter, contacts`15`5 and 156 opens the circuit to relay 160. Relay 160 restores, opening contacts 161 to stop the under. A selector switch (not shown) linked with tinder 301 would return dial tone in a well-known manner, and the calling party would proceed to dial the desired directory number to extend the call in a Well-known manner over a switch train.

Assuming that an incoming call to the oflice Station A via incoming connector 5 has been initiated, should this line be idle, the control wiper of connector 5 would engage battery on the connector terminal extending via conductor C14, contacts 122', and Winding of relay 110. Relay 11i]I would operate from ground in the connector 5 to operate its X contacts tirst; however, contacts 114 would close but would be ineiective on incoming calls. The X contacts 115 lwould close a circuit to relay 130 providing the residence line telephone at station B is not in use. Assuming it is not in use, the circuit to relay .130 would extend from ground, contacts 115, 128, 151, the timer spring contacts 276, winding of rel-ay 130 to battery. Thereafter, contacts `111 would open to prevent any false operation of relay 12). Contacts 113 closes ground Via contacts 125 and conductor MTRS to operate the incoming call totalizer meter to register an incoming call to Line 1. lf the residence line was in use at this time, relay 150 would be operated and contacts 151 would be open to prevent operation of relay 130. Assuming, however, that relay 130 does operate,

contacts 132 would close to prepare a circuit to the transfer to Line 2 meter. At contacts 133 and 134 a circuit to ringing relay 220 is prepared. At contacts 135 circuits are prepared to relay 250y and motor magnet 260. Contacts 137 close a locking circuit to relay 130 via contacts 128 and 115. Contacts 138 and 139 close to prepare a circuit to relay 240.

Upon receipt of the ringing over the negative side of the line, the ringer 7 at Station A would respond and ringing relay 220 would respond to the generator over a circuit including negative conductor C12, contacts 133, 211, Winding of relay 220, capacitor 225, contacts 134, and over the positive conductor C13. Relay 230 is slowto-operate so that it will not respond to any momentary flash which it might receive from ringing relay 220 closing contacts 221, :and this makes it sloW-to-operate so that it will operate only once for each ringing period. Relay 230 operating, closes ground to motor magnet 260 via contacts 241, to cause energization thereof, However, motor magnet 260 is of the type that steps on deenergization so that it will not advance the cams of timer 270 until the end of the ringing period, at which time relays 220 and 230 restore to open contacts 231. At the end of the first ringing period, the motor magnet will have stepped the cams C1C4 of timer 270 from the first position to position 2 as designated in vertical lines in FIG. 2 whereby springs 281, 282, and 283 will not be affected, but spring 284 will disengage lugV 294. This last disengagement will open cam spring contacts 276 and open the operating circuit to relay 130, however, relay 130 remains operated over its mentioned locking circuit. Cam spring contacts 277 open a prepared circuit to relay 180, and cam contacts 278 prepares a self-interrupter circuit to motor magnet 260.

Should the call be answered promptly by the subscriber at Station A, ringing will cease and ringing relay 220 cannot operate. This prevents the motor magnet 260 from advancing the cams C1-C4 any further. At this time, conversation Will be taking place between the calling party and the called party at substation A. However, if the ringing continues, the cams C11-C4 will advance one step `for each cessation of ringing periods. If, after four ringing periods are had and thecalled party stillhasnt answered, the cams C1-C4 will be in their respective fifth positions, whereby cam spring 282 Will engage lug 292 on cam C3, closing cam contacts 274 to operate ring cut-olf relay 210 via ground at contacts 135. Also, cam contacts 273 close a self-interrupted circuit to motor magnet 260; the circuit extending from battery, winding of motor magnet 260, contacts 261, 273, 272, 135 to ground. Relay 216 operating opens `at contacts 211 the ringing circuit to relayV 22:1)` so that it can no longer operate relay 230 to energize the motor magnet 260. At contacts 212 ground is closed via contacts 139 and control conductor C to busy the connector bank `corresponding to Line 2, and operates relay 158` via contacts 164. Relay 150, in operating, opens contacts 155 and 156 to prevent any false operations of relay 168, and `at contacts 154 closes ground via contacts `173 `and conductor MTR6 to the incoming call totalizer meter for Line. 2 to register rthe call. Motor magnet 261i, by means of its self-interrupter contacts 261, will deenergize motor magnet 268 and step the cams C1-C4 to the sixth position, lwhereby cam spring 281 of cam C4 will engage lug 291. This last engagement will cause contacts 272 to open the self-interrupter circuit to motor magnet 260. Cam contacts 271 will close an obvious circuit to transfer relay 250. Relay 258 operates closing at contacts 251 a circuit to the transfer to Line 2 meter for metering purposes via contacts 132 and conductor MTR4. At contacts 252 and 253, Line 1 is connected to Line 2 so that the iifth ringing period will now ring both lines land whichever line is the iirst to `answer will cut oi the ringing. Since this ringing took place over the negative side of the line, only ringer 8 at Station B would have responded in series with ringer 7.

When the call is terminated and the switch train is released, ground is removed from CN lead C14i on Line 1 to open the circuit to relay 1102 Relay 110 restores, opening at X contacts 115 the locking circuit to relay 130. Relay 130 restores, opening at contacts 135 the circuit to relays 218 and 258. Relay 219 restores, opening at contacts 212 the circuit to relay 150, and also removes busy ground from CN lead C25 to avail Line 2 for seizure. Relay 258 restores to disconnect Line 1 from Line 2 at contacts 252 and 253. At contacts 136 ground is closed via contacts 184, 278, and 261 and through the winding of motor magnet 260 to battery, to cause energization thereof. Motor magnet 268,- by means of its self-interrupter contacts 261, will interrupt its circuit to deenergize motor magnet 268' to step the cams C1-C4 to their respective normal position, namely position l. The timer switch 270 returning to position l will actuate spring 284 to open the interrupter circuit to motor magnet 260 at contacts 278.

If Line 2 is idle when Line 1 is called, but becomes busy after relay 130 is operated, and before cams C1-C4 reach position 5, ground on CN lead C25 Will operate relay 240 when the timer switch 278 gets to position 4. This last circuit extending from battery, winding of relay 240, contacts 138, contacts 275 (spring 283 engaging lug 293), 139 to ground on CN lead C25. Relay 248, in operating, opens contacts 241 so that the pulsing circuit to motor magnet 268 is opened and the timer switch 270 will not respond to the fourth ringing period. Thus, the timer switch 279` is prevented from advancing so that Line -1 is not connected to Line 2 when Line Zeis busy. Contacts 242 closes ground to the transfer failure meter via contacts 189 and conductor MTRZ to register a failure or delay in transferring a call to Line 2. if the party calling Line 1 should hang up without the call being `answered and while Line 2 is still busy, relays 118 and 130 will release in a manner previously described. Relay 130, in restoring, opens contacts 138 and 139 to open the circuit to relay 248. At contacts 136 relay `138 will close a self-interrupter circuit to motor magnet 268 to home the timer switch. Relay 188* being the equivalent of relay -130 with respect to Line 2 cannot operate while the timer switch 278 is homing because cam 1 has the circuit opened. Relays 210 and 228` cannot operate either because neither relay 130 nor 188 are operated. However, if the party calling Line 1 waits for an answer until Line 2 is free, removal of ground from CN lead C25 of Line 2 will permit relayl 240 to restore. The restoration of relay 240 would then let relay 228' close the pulsing circuit to motor magnet 269 at the next ringing periodto initiate the transfer previously described.

A transfer of a call from Line 2 to Line 1 is made in 8 the same general manner as calls transferred from Line 1 to Line 2. As mentioned, the residence station has two directory call numbers. Assuming iirst a business call to the doctor, an incoming call having the last digit corresponding to the bank contacts Y on connector 6, battery encountered on the control contact by the connector wiper will close ground over CN conductor C25 to operate relay 150. Relay operating closes its contacts iirst, whereby a circuit is closed to relay 188 via ground, X contacts 153, contacts 172, 116, 277, winding of relay to battery. Thereafter, contacts 151 open a prepared circuit to relay 130. Contacts 154 close a circuit via contacts 173 and conductor MTRt to the incoming call totalizer meter for Line 2. Relay 180` operates closing contacts 181 `and 182 to prepare a circuit to relay 248. Contacts l1835 close to prepare a circuit to transfer relay 250. At contacts 185 relay 188 closes a locking circuitfor itself via contacts 172 and 153. Contacts 186 and 187 close to connect ringing relay 228 to the incoming loop conductors C24 and C25 in series -with the called partys ringer 8 at Station B. Contacts 188 close to prepare a circuit to the transfer failure meter over conductor MTRI.

Since the call is intended for the doctor and came in over contacts Y of `connector 6, the ringing frequency would come in over the negative side of the line via negative conductor C23 to ringer y8 and ground, to ring this ringer only. Also, ringing relay 220 will respond in a manner previously described, to close a circuit to relay 230. Relay 230 in turn, will close a circuit to motor magnet 260 in a manner previously described. The remainder of the operations will be generally similar to that described with respect to incoming calls to lLine 1, with the exception of different paths of operation. For instance, if `four ringing periods have expired and no answer has taken place at residence Station B, the timer switch 270 will be in position 5 and relay 210` will operate over a circuit including contacts 274, 183, and 136 to ground, and a circuit to motor magnet 250 is closed over contacts 261, 273, 272, 183, and 136 to ground. It is to be understood that since ringer 8 rang at residence station B, the tone of ringer 8 being different than ringer 9 would designate that the call is intended for the doctor, and if it were known that the doctor was in his office, the call need not be answered, but a resident would wait for the timer to transfer the call to Line 1. Relay 218 operates, opening contacts 211 to open the ringing circuit to relay 220, and contacts 212 close ground via contacts 181 and CN lead C14 to mar-k Line 1 as busy, and operate relay 110 via contacts 122. Motor magnet 268 lby means of its contacts 261 will self-interruptcdly step the cams C1-C4 to their respective sixth position to open at cam contacts 272 the circuit to motor magnet 268, and close a circuit to transfer relay 258 at cam contacts 271. The last circuit extending from battery, winding of transfer relay 250, cam contacts 271, contacts 183, and 136 to ground. Relay258 operates, closing contacts 251 to operate the transfer to Line 1 meter via a circuit including contacts 131 and conductor MTRS. At contacts 252 and 253 the ringer 7 of the oflice Station A is closed in multiple with the ringer 8 of residence Station B, whereby both ringers will respond by ringing responsive to the fifth ringing period. The above operations will all take place `before receipt of the tifth ringing period. The iirst station to answer will cut olf the ringing.

If Line 1 is idle when Line 2 is called, but Line 1 lbecomes busy after relay 188 has already operated and before the cams reach position 5, ground on CN conductor `C14 of Line A1 will operate relay 240 when the cams are advanced to position 4. This last circuit extending from battery, winding of relay 248, contacts 1182, 275, 181, conductor C14 to ground via the control wiper of the incoming connector. Relay 240 will thus openthe pulse circuit to ythe motor magnet so the timer 270 will not respond to the fourth ringing period. Thus, the

transfer cannot be made to a busy line. YIt the lparty calling Line 2 should hang up lwithout the call being answered and while Line 1 is still busy, relays 150 and 184i Will restore, and relay 18d will restore relay 240. Relay 180 will close a self-interrupter circuit to motor magnet 260 to home the timer over a circuit including ground, contacts 136, 184, 278, 161, Winding of motor magnet 216e to battery.

If the party calling Line 2 waits for an answer until Line 1 is free, removal of ground from CN conductor C14 of Line 1 will le-t relay 240 restore. The restoration of relay 240 will now'permit relays 220 and 230 to close the circuit to motor magnet 260 at the next ringing period, and the transfer operation is initiated as previously described.

On incoming calls having a directory number corresponding to bank contacts Z on connector `6, the above operations would take place except that this is a normal residence ca'll whereinV the ringing frequency would be transmitted over the positive side of the line via positive conductor C24 to ring ringer 9. A resident at Station B would then know by the tone of ringer 9 that this is a non-business call and would answer the call. However, should said lresident -fail to answer the call after tour ringing periods, the above-described transfer would take place, providing Line 1 is not busy, but since the ringing fre quency is transmitted over the positive side of the line the ringer 7 would not respond since it is on the negative side of the line. Therefore, if the doctor were in his ofce at this time, the non-business call would not disturb him for unnecessary reasons. To avoid beingr confused as to whether the call is a business or non-business call by relying on the tones of the lingers, two separate telephones could be utilized at Station B, however, maintaining the same single line for both calls, -bu-t having ringers 8 and 9 in separate telephones. This way, theresident could tell whether the call was a business call or a nonbusiness call by determining which telephone has been rung. Y

Thevinvention having ybeen described, that which is believed to be new and for which the protection of Letters Patent is desired will be pointed out in the appended claims. f

What is claimed is:

l. In a telephone system; a pair of lines each having a ringer connected thereto; a line circuit common to both said lines; a source of interrupted ringing current; means for extending a calling connection, including said ringing current, to one vof said lines and to said line circuit; said ringer associated with said one line `being thereafter operated in response to receipt of said interrupted ringing current; ringing current responding means in said line circuit; means in said line circuit operated in response to said calling connection :being extended thereto for further extending said connection to said ringing current responding means; said ringing current responding means operating in accordance with the receipt of said interrupted ringing current; and control means in said yline circuit operated by each `said operation of said ringing current responding means for extending said calling connection to the other of said pair of lines after the termination of a predetermined number of said responding means operations; said ringer associated with said other line thereafter operating simultaneously with said operation of said ringer of said one line in response to said last mentioned extension of said connection to said other line.

2. In a telephone system such as claimed in claim l; wherein said last mentioned means includes timing apparatus operated by each said operation of said ringing current responding means tor registering each of said responding means operation; relay means; means controlled by said timing apparatus after said registering of a predetermined number of said responding means operations for operating said relay means; and means operated by Y 8 Y said operation of said relay means for connecting said calling connection with said other of said pair of lines.

3. In a telephone system such yas claimed in claim l; includingbusying means in said line circuit individual to said other line of said pair; means operated in response to said other line being taken into use, before said calling connection is extended thereto, for operating said busying means; and means operated in response to said operation of said busying means after a dierent predetermined number of operations of said control means for blocking said extension of said calling connection to said other line.

4. In a telephone system; an oice line-having a telephone subscriber station thereon; a residence line having a telephone subscriber station thereon; a line circuit common to both said lines; a source of interrupted ringing current; a lrst connector switch having access to said otice line and a second connector switch having access to said residence line for extending calling connections thereto including said ringing current; means operated in response to the extension of a calling connection to one of said lines by one or said connectors upon receipt of said ringing current for signalling the corresponding subscriber station of an incoming call; means in said line circuit operated in response to said extension of said calling con nection to said one line for extending said connection further into said line circuit; timing means intermittently operated in response :to receipt of said interrupted ringing current received over said further extended connection for connecting said other line with said one line after the termination of a predetermined number of said intermittent timing means operations; and means op erated in response to said connection of said other line with said one line upon receipt of said ringing current for signalling the other said subscriber station simultaneously with said signalling of said one subscriber station.

5. In a telephone system; a residence line having a lirst and a second ringer connected thereto; an oice line having an otiice line ringer connected thereto; a common line circuit connected to both said residence and said oliice lines; a source of interrupted ringing current; means for selectively extending calling connections, including said ringing current, to said residence line to operate either said first or said second ringer in accordance with a rst or a second selective extension; means in said line circuit operated in response to receipt of said ringing current received over a calling connection selectively extended to said first ringer on said residence line for registering the interruptions of said ringing current; and relay means in said line circuit operated in response'to said registering of a predetermined number of said ringing current interruptions for connecting said otice line with said residence line; whereby said oce line ringer and said first ringer are thereafter simultaneously operated by said ringing current.

6. In a telephone system such as claimed in claim 5; including means in said line circuit operated in case said oiiice line is taken into use, before said connection of said oce line is made with said residence line, for disabling further operation of said last mentioned means to discontinue said registering of'said ringing current interruptions.

7. In a telephone system wherein a common subscriber has an otlce line at one location and a residence line at a diiierent location; said oliice line including a pair of line conductors having a first ringer connected to one of said conductors for signalling said subscriber thereover; said residence line including a pair ofline conductors having a second ringer connected to the conductor corresponding to said one oice conductor and a third ringer connected to the other of said conductors, each for signalling said subscriber thereover; a iirst and a second source of interrupted ringing current; first switching means for extending calling connections, including said first4 ringing current, to said otiice line to operate said first ringer; second switching means for selectively extending calling connections, including said second ringing current, to said residence line to operate either said second ringer in accordance with a particular selected extended connection or said third ringer in accordance with a diierent selected extended connection; common means in said line circuit; rst individual means in said line circuit operated in response to the extension of a calling connection, including said rst ringing current, to said otiice line by said iirst switching means for further extending said calling connection to said common means; said common means being thereafter operated in response to receipt of said first vringing current; connect means operated in response to a predetermined number of said operations of said common means for connecting said residence line with said office line; whereby receipt of said r-st ringing current over said existing connection simultaneously operates said rst and said second ringers to signal said subscriber over both said ofiice and said residence lines; second individual means in said line circuit operated in response to the extension of said particular selected calling connection, including said second ringing current, to said residence line by said second switching means for further extending said particular selected calling connection to said common means; said common means being thereafter operated in response to receipt of said second ringing current; said connect means operated in response to a predetermined number of said operations of said common means for connecting said oice line with said residence line; whereby receipt of said second ringing current over said existing particular selected connection simultaneously operates said second and said iirst ringers to signal said subscriber over both said residence and said oce lines, said second individual means operatedV in response to the extension of said diierent selected calling connection, including said second ringing current, to said residence line by said second switching means for further extending said diierent selected calling connection to said common means; said common means being thereafter operated in response tov receipt of said second ringing current; and said connect means operated in response to a predetermind number of said operations of said common means for connecting said oce line with said residence line; whereby receipt vof said second ringing current over said existing different selected connection operates said third ringer to signal said subscriber over only said residence line.

8. In a telephone system such as claimed in claim 7; including residenceline busying means in said line circuit; means operated in response Ito said residence line becoming busy, before said connection of said residence line with said office line, for operating said residence line busying means; blocking means operated in response to said operation of said residence line busying means after a different predetermined number of said operations of said common means for disabling said operation of said connect means to block said connection of said residence line with said oce line; oice line busying means in said line circuit; and means operated in response to said oiiice line becoming busy, before said connection of said office line with said residence line, for operating said oice line busying means; said blocking means operating in response to said operation of said otTice line busying means after said different predetermined number of said operations of said common means for disabling said operation of said connect means to block said connection of said otlice line said residence line.

9. In a telephone system, an oiiice line having a rst ringer for signaling a subscriber thereat, a residence line having a second ringer for signaling the same subscriber at a location remote from said office line, a line circuit, a tirst means in said line circuit individu-a1 to said office line, a second means in said line circuit individual to said residence line, and a third means in said line circuit common Ito both lines, said iirst means operated to prepare said third means for operation responsive to an incoming call to said office line, said second means operated to prepare said third means for operation responsive to an incoming call to said residence line, a source of interrupted ringing current transmitted on incoming calls to their line for intermittently ringing lthe ringer corresponding to the line called, said third means operated responsive to a predetermined number of intermittent rings for connecting an incoming callkfrom said office line to said residence line or form said residence line tov said office line depending upon the line being called, and said iirst and second means eiectively operated to prevent the operation of said third means in the event one of said lines is busy at a time when saidother line is being called.

10. In a telephone system, a irst line having a substation and a lfirst ringer thereon, a second line having a substation and a second ringer thereon, a line circuit, a firs-t plurality of relays in said line circuit individual to said first line, a second plurality of relays in said line circuit individual to said second line, a timer switch in said line circuit comprising a plurality of predetermined stepped positions, a ringing relay in said line circuit common to first and second lines, a source of series of interrupted ringing current transmitted intermittently ring said first ringer and intermittently operated said ringing relay responsive to an incoming call to said rst line and transmitted to intermittently ring Said second ringer and intermittently operated said ringing relay responsive to an incoming call to said second line, circuit means controlled by each intermittent operation of said ringing relay for stepping said timer switch one step for each intermittent operation thereof, a transfer relay in said line circuit operated responsive to said timer switch being ,stepped to a irst predetermined position to interconnect said first line to said second line to cause said first and second ringers to simultaneously ring responsive -to the next series of interrupted ringing current transmitted regardless of which lines is being called, and disabling means operated responsive to an incoming call to said iirst line at a time when said second line is busy to disable said timer switch and prevent the transfer.

11. In a telephone system as claimed in claim 10, in

cluding a second disabling means operated to disable said timer switch responsive to said timer switch being stepped to a second predetermined position on an incoming call to said iirst line followed by an incoming call to said second line.

References Cited in the le of this patent UNITED STATES PATENTS 1,866,639 yFeind July 12, 1932 1,905,711 Hinrichsen Apr. 25, .1933 2,312,385 Burgener Mar. 2, 1943 2,358,017 Lomax Sept. 12, 1944 2,718,560 Alexandersson Sept. 20, 1955 2,892,038 Gatzert June 23, 1959 

